1. Field of the Invention
The present invention generally relates to a KVM extender system, and more particularly to a KVM extender system transceiving data packets, audio signals and video signal with a cable therebetween.
2. Description of Prior Art
A KVM extender system can allow a console user to access a computer coupled therewith for a remote control solution with a longer communication distance. When the console user accesses the computer, the keyboard/video/mouse control function to the computer is essential and the only purpose of the KVM extender in general. However, the console user may need to operate the computer remotely and download some operation data from the computer to the console. Furthermore, the console user may also need to upload some data to the computer, such as, execution of installing software program, updating operation system, backing up operation data or etc. A storage function for the KVM extender becomes a necessity of aforesaid operations.
However, the present KVM extenders do not support the storage function for the console user. Moreover, a general USB extender which extends transmission length of cable in HUB linking only extends the downstream ports, such as, disclosed in U.S. Pat. No. 6,584,519. Such USB extender only considers USB data transmission. The keyboard, mouse, audio and sound data transmissions are not included in its consideration, not to mention complicated video transmission which is important in a KVM extender system. The KVM extender system includes two extenders each utilizing a RS485 transceiver and a UART connected thereto for transceiving signals. Furthermore, another kind of USB extender which extends transmission length of cable in RS485 UART linking which the max baud rate is not more than 1 M bps generally and limits the speed of operating storage.